1. Field of the Invention
The present ivention concerns an electrical transmission ring assembly designed to be mounted between the steering column and the steering wheel of an automobile vehicle in order to provide a rotational electrical connection between the switch controlling various functions placed on the steering wheel and the receiving units of the devices to be controlled.
2. Description of the Prior Art
In current automobile vehicles the driver is provided with an increasingly large number of electrical and electronic devices (onboard computer, radio, cruise control, etc.) the controls for which, complementing the conventional devices (turn indicators, lighting, windshield wipers, etc) are placed on the dashboard and around the steering wheel. It is not always easy to operate all these controls, especially when the vehicle is moving, in which case it can even be hazardous.
With a view to bringing all of the aforementioned functions together on the steering wheel, within easy reach of the driver, it has been proposed to employ transmission rings consisting of a first series of conductive rings fastened to a bush fixed to the steering column and cooperating with a second series of conductive rings fastened to a base member in turn attached to so as to rotate with the steering wheel, each pair of contacts formed by one ring from each of the two series being separated from adjacent pairs by means of an insulative member.
For a more detailed description of the aforementioned transmission ring assembly reference may be had to published European Patent Application No. 0150644. Although the transmission ring assembly as previously described makes it possible to enhance substantially the functioning of known transmission systems as used heretofore, the significant increase in the number of transmission paths has resulted in the fact that the making of connections from conductive wires to the conduction tracks eventually gives rise to problems with the mechanical durability of the aforementioned conduction tracks because of mechanical stresses exerted by the electrical conductors connecting the receiving units or effectors to one or other of the rings of the first or second series, by virtue of the large number of to-and-fro rotation movements made by the driver in use.
An object of the present invention is to remedy the aforementioned disadvantages through the use of a transmission ring assembly in which the connection and contact functions of each conductive ring in each of the first and second series are substantially separated.
Another object of the present invention is the use of a transmission ring assembly having significantly enhanced reliability, both mechanically and electrically, as compared with prior art systems.
A further object of the present invention is to simplify the implementation of a transmission ring assembly in accordance with the invention by virtue of the inherent design of the conductive rings of the first and second types.